Single-stage class-AB amplifiers are among the most effective amplifiers for SC circuits. Single-stage amplifiers have only one current path and achieve a high dynamic range in class-AB operation. SC circuits are driven according to the principle of switched capacitors and are also referred to as switched-capacitor circuits.
A class-AB operation of an amplifier is classified by its operating point, among other things. Floating voltage sources or batteries are frequently used to suitably adjust the operating point. They typically comprise capacitors and must be charged periodically in charging cycles. Operation of the amplifier is impossible during a charging process.
Various approaches to a solution of this problem have so far been proposed. For example, an SC amplifier can be operated by direct DC coupling during a charging cycle. However, this leads to asymmetrical biasing with different input and output operating points. It is also disadvantageous to provide a charging phase differing from the operating state of the amplifier.